One Canada Square (also known as the Canary Wharf Tower) is a skyscraper in Canary Wharf, London, England. It is the tallest building in the United Kingdom at 235 metres (771 ft) above ground level. At 50 storeys, it is a London landmark with a distinctive pyramid pinnacle at 244 metres (801 ft) above sea level.

One Canada Square achieved the title of tallest skyscraper in the UK in August 1991, a record which it has held since. However, there are currently three skyscrapers under construction that will overtake One Canada Square in terms of height: Riverside South, Bishopsgate Tower and The Shard.